In the UK, for a long time there have been adverts on the side of buses proclaiming some religious thing or other. The Humanist Association decided to make a campaign of their own saying 'There is probably no God, now go out and enjoy yourself'. The original campaign was to raise a few thousand pounds, but this rapidly grew to £140000.

"Even on the buses, nobody thinks twice when they see a religious slogan plastered across the side.

"This campaign to put alternative slogans on London buses will make people think - and thinking is anathema to religion."

Christian Voice, ironically had this to say:

"People don't like being preached at. Sometimes it does them good, but they still don't like it."

It is true that The Humanist Association cannot prove the existence or non-existence of God, hence the word 'probably' (Carlsberg did a similar trick) - but for the advertising standards agency to find against these ads, they also have to find against all religious ads. After all, by a process of elimination, only one of the claims can be correct, can't it?